Source/core/platform/graphics/win/FontCustomPlatformDataWin.cpp

/*
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#include "config.h"
#include "core/platform/graphics/FontCustomPlatformData.h"

#include "platform/LayoutTestSupport.h"
#include "platform/NotImplemented.h"
#include "platform/SharedBuffer.h"
#include "core/platform/graphics/FontPlatformData.h"
#include "core/platform/graphics/opentype/OpenTypeSanitizer.h"
#include "core/platform/graphics/opentype/OpenTypeUtilities.h"
#include "wtf/PassOwnPtr.h"
#include "wtf/RefPtr.h"
#include "wtf/text/Base64.h"

#include <objbase.h>

namespace {

// Creates a unique and unpredictable font name, in order to avoid collisions and to
// not allow access from CSS.
String createUniqueFontName()
{
    GUID fontUuid;
    CoCreateGuid(&fontUuid);

    String fontName = base64Encode(reinterpret_cast<char*>(&fontUuid), sizeof(fontUuid));
    ASSERT(fontName.length() < LF_FACESIZE);
    return fontName;
}

} // namespace

namespace WebCore {

FontCustomPlatformData::FontCustomPlatformData(HANDLE fontReference, const String& name)
    : m_fontReference(fontReference)
    , m_name(name)
{
}

FontCustomPlatformData::~FontCustomPlatformData()
{
    if (m_fontReference)
        RemoveFontMemResourceEx(m_fontReference);
}

FontPlatformData FontCustomPlatformData::fontPlatformData(float size, bool bold, bool italic, FontOrientation orientation, FontWidthVariant)
{
    ASSERT(m_fontReference);

    LOGFONT logFont;
    // m_name comes from createUniqueFontName, which, in turn, gets
    // it from base64-encoded uuid (128-bit). So, m_name
    // can never be longer than LF_FACESIZE (32).
    if (m_name.length() + 1 >= LF_FACESIZE) {
        ASSERT_NOT_REACHED();
        return FontPlatformData();
    }
    unsigned len = m_name.copyTo(logFont.lfFaceName, 0, LF_FACESIZE - 1);
    logFont.lfFaceName[len] = '\0';

    // FIXME: almost identical to FillLogFont in FontCacheWin.cpp.
    // Need to refactor.
    logFont.lfHeight = -static_cast<int>(size);
    logFont.lfWidth = 0;
    logFont.lfEscapement = 0;
    logFont.lfOrientation = 0;
    logFont.lfUnderline = false;
    logFont.lfStrikeOut = false;
    logFont.lfCharSet = DEFAULT_CHARSET;
    logFont.lfOutPrecision = OUT_TT_ONLY_PRECIS;
    logFont.lfQuality = isRunningLayoutTest() ? NONANTIALIASED_QUALITY : DEFAULT_QUALITY; // Honor user's desktop settings.
    logFont.lfPitchAndFamily = DEFAULT_PITCH | FF_DONTCARE;
    logFont.lfItalic = italic;
    logFont.lfWeight = bold ? FW_BOLD : FW_DONTCARE;

    HFONT hfont = CreateFontIndirect(&logFont);
    return FontPlatformData(hfont, size, orientation);
}

PassOwnPtr<FontCustomPlatformData> FontCustomPlatformData::create(SharedBuffer* buffer)
{
    ASSERT_ARG(buffer, buffer);

    OpenTypeSanitizer sanitizer(buffer);
    RefPtr<SharedBuffer> transcodeBuffer = sanitizer.sanitize();
    if (!transcodeBuffer)
        return nullptr; // validation failed.
    buffer = transcodeBuffer.get();

    // Introduce the font to GDI. AddFontMemResourceEx should be used with care, because it will pollute the process's
    // font namespace (Windows has no API for creating an HFONT from data without exposing the font to the
    // entire process first).
    String fontName = createUniqueFontName();
    HANDLE fontReference = renameAndActivateFont(buffer, fontName);
    if (!fontReference)
        return nullptr;

    return adoptPtr(new FontCustomPlatformData(fontReference, fontName));
}

bool FontCustomPlatformData::supportsFormat(const String& format)
{
    return equalIgnoringCase(format, "truetype") || equalIgnoringCase(format, "opentype") || OpenTypeSanitizer::supportsFormat(format);
}

} // namespace WebCore